Practice question

Dithecous anther comprises two distinct lobes thecae joined by connective tissue housing vascular strand, each lobe encloses two microsporangia pollen sacs, totaling four pollen sacs that undergo microsporogenesis meiosis producing haploid pollen grains. Bilobed tetrasporangiate structure is plesiomorphic for most angiosperms. Two pollen sacs define monothecous condition as in Malvaceae, single sac exceptional reduction, absence indicates sterile staminode. Four-sac organization ensures higher pollen output per anther, characteristic of ancestral angiosperm stamen. Internal anatomy in cross section reveals epidermis, fibrous endothecium, middle layers and nutritive tapetum nourishing developing microspore tetrads.